From: Huacai Chen chenhuacai@loongson.cn
Previously we selected the firmware default device, i.e., one that owns the boot framebuffer, as the default device in vga_arb_select_default_device(). This was only done in the vga_arb_device_init() subsys_initcall, so devices enumerated later, e.g., by pcibios_init(), were not eligible.
Fix this by moving the firmware default device selection from vga_arb_select_default_device() to vga_arbiter_add_pci_device(), which is called after every PCI device is enumerated, either by the vga_arb_device_init() subsys_initcall or as an ADD_DEVICE notifier.
Note that if vga_arb_select_default_device() previously found a device owning the boot framebuffer, it unconditionally set it to be the default VGA device, and no subsequent device could replace it.
[bhelgaas: commit log, restructure slightly] Link: https://lore.kernel.org/r/20211015061512.2941859-7-chenhuacai@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn Cc: Bruno Prémont bonbons@linux-vserver.org --- drivers/pci/vgaarb.c | 37 +++++++++++++++++-------------------- 1 file changed, 17 insertions(+), 20 deletions(-)
diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index 58e0a12e623b..c3323ab4f98e 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -72,6 +72,7 @@ struct vga_device { unsigned int io_norm_cnt; /* normal IO count */ unsigned int mem_norm_cnt; /* normal MEM count */ bool bridge_has_one_vga; + bool is_firmware_default; /* device selected by firmware */ unsigned int (*set_decode)(struct pci_dev *pdev, bool decode); };
@@ -565,10 +566,9 @@ void vga_put(struct pci_dev *pdev, unsigned int rsrc) } EXPORT_SYMBOL(vga_put);
-static void __init vga_select_framebuffer_device(struct pci_dev *pdev) +static bool vga_is_firmware_default(struct pci_dev *pdev) { #if defined(CONFIG_X86) || defined(CONFIG_IA64) - struct device *dev = &pdev->dev; u64 base = screen_info.lfb_base; u64 size = screen_info.lfb_size; u64 limit; @@ -583,15 +583,6 @@ static void __init vga_select_framebuffer_device(struct pci_dev *pdev)
limit = base + size;
- /* - * Override vga_arbiter_add_pci_device()'s I/O based detection - * as it may take the wrong device (e.g. on Apple system under - * EFI). - * - * Select the device owning the boot framebuffer if there is - * one. - */ - /* Does firmware framebuffer belong to us? */ for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { flags = pci_resource_flags(pdev, i); @@ -608,13 +599,10 @@ static void __init vga_select_framebuffer_device(struct pci_dev *pdev) if (base < start || limit >= end) continue;
- if (!vga_default_device()) - vgaarb_info(dev, "setting as boot device\n"); - else if (pdev != vga_default_device()) - vgaarb_info(dev, "overriding boot device\n"); - vga_set_default_device(pdev); + return true; } #endif + return false; }
static bool vga_arb_integrated_gpu(struct device *dev) @@ -635,6 +623,7 @@ static bool vga_arb_integrated_gpu(struct device *dev) static bool vga_is_boot_device(struct vga_device *vgadev) { struct vga_device *boot_vga = vgadev_find(vga_default_device()); + struct pci_dev *pdev = vgadev->pdev;
/* * We select the default VGA device in this order: @@ -645,6 +634,18 @@ static bool vga_is_boot_device(struct vga_device *vgadev) * Other device (see vga_arb_select_default_device()) */
+ /* + * We always prefer a firmware default device, so if we've already + * found one, there's no need to consider vgadev. + */ + if (boot_vga && boot_vga->is_firmware_default) + return false; + + if (vga_is_firmware_default(pdev)) { + vgadev->is_firmware_default = true; + return true; + } + /* * A legacy VGA device has MEM and IO enabled and any bridges * leading to it have PCI_BRIDGE_CTL_VGA enabled so the legacy @@ -1531,10 +1532,6 @@ static void __init vga_arb_select_default_device(void) struct pci_dev *pdev, *found = NULL; struct vga_device *vgadev;
- list_for_each_entry(vgadev, &vga_list, list) { - vga_select_framebuffer_device(vgadev->pdev); - } - if (!vga_default_device()) { list_for_each_entry_reverse(vgadev, &vga_list, list) { struct device *dev = &vgadev->pdev->dev;